Recent Posts

Pages: 1 ... 7 8 9 [10]
Q & A / Original Two Prong Power Cord
« Last post by N2000s on July 20, 2017, 08:43:26 am »
Hey guys, Posted this over at another site... but wanted to check here too.

 I'm looking for a original Sunn 2 prong power cord from around 68-70. Currently the amp has an updated plug but the new owner will be using this in a museum type setting and he's interested in keeping it as original as possible. Anyone have one around in great shape that they are willing to part with?

If so send a message or email me at: and we can work out the details. Thanks!!!
Q & A / Sunn Coliseum
« Last post by jakesforbrakes on July 19, 2017, 08:06:39 am »
Hi There! I just acquired the Sunn Coliseum on top with red knobs/black face. It's in the shop being serviced and we're having a hard time identifying the correct model number so that we can get the right schematics. Can anyone here help me out? Thanks!!!
Q & A / Re: Ohms of the spectrum 1
« Last post by Soundmasterg on July 18, 2017, 02:18:28 pm »
With all of the Sunn amps, the output transformer has taps for 4 ohms, 8 ohms, and 16 ohms. It will have negative feedback tied to one of them inside the amp, and then one of the other ones will be connected to the back, either 8 ohms or 16 ohms, with another one connected to the extension speaker jack which is a switching jack. They utilized different transformer taps on the back of the amp from year to year, but you should be able to look at the back of the amp and see which one they were was usually labeled.

I can look later when I get home and see if I have the schematic available for you. Maybe one of the others will chime in too.....

Q & A / Ohms of the spectrum 1
« Last post by Wizardsleeves on July 18, 2017, 10:56:04 am »
Hi everyone
I bought a spectrum 1 yesterday. Loving it so far we'll see how it holds up. My question is what are the ohms the spectrum 1 puts out with one speaker and what with two?
Thank you
DIY / Re: Closest SUNN Model T clone ever?
« Last post by _peter on July 17, 2017, 11:38:10 pm »
Hi Marco,

thanks! I played it through two London City cabs loaded with Celestions...
G12H30s I believe, but not 100% sure.

Q & A / Re: schematics? where is the schematics download location?
« Last post by Wizardsleeves on July 17, 2017, 04:47:02 pm »
I'm looking for a schematic for the Sun Spectrum 1. No luck on the Hoffman site. Any pointers, anyone? Greatly appreciated, thanks.
DIY / Re: Removing Paint from Tolex
« Last post by N2000s on July 14, 2017, 09:01:18 pm »
I tried everything and what worked the best was the "GOJO Orange hand cleaner." That and a wire brush did very well on an amp I had.
DIY / Re: Closest SUNN Model T clone ever?
« Last post by Fuzzonaut on July 12, 2017, 05:57:30 am »
Hi Peter,

Well, I think this is amazing! Well done!

If it sounds just half as good as it looks, whoever can plug into it must be very, very happy.
What cab is used with it?


Q & A / Re: Cone Excursion
« Last post by Isaac on July 11, 2017, 08:07:27 am »
Sounds as though you have the problem solved, Eddie. What I think was happening, touched on by both G and Ed, was that the high fidelity, full range amp was putting out frequencies that were lower than the tuning frequency of the speaker cabinet. When that happens, the driver is no longer loaded acoustically. That is, there is no "air spring" to prevent the driver from flopping about, and can lead to the driver exceeding its excursion limits and even damaging the driver. Using a high pass filter, as you are doing, will prevent that. As G mentioned, tube amps have lower damping factors, and a high damping factor will also help by electrically suppressing excessive excursion.

A lot of amps, even old Sunn tube amps, limit frequency response. IIRC, the 200S rolls off the low end at 80Hz, 40Hz with the LOW BOOST engaged (so it's not really a low boost, just extending the low end by an octave). I don't see a lot of cone excursion when using the 200S. On the other hand, I don't think that the Sceptre line (and my Sentura, etc.) are rolled off anywhere near that high. There's a -6dB shelf in the response on the low end (I don't remember the frequency), but the low end roll off occurs much lower, which is one reason those amps make such nice bass amps. And with my Sentura II, I do see much higher cone excursion.
Q & A / Re: Cone Excursion
« Last post by Soundmasterg on July 10, 2017, 06:08:12 pm »
  By the way, Soundmasterg, I am in your debt.  Your postings about cap replacement, in our modern age, has been my guide to reconditioning my amp.  Thanks!

You're welcome, glad to help!

Pages: 1 ... 7 8 9 [10]